Desk with expansible legs

ABSTRACT

In order to simplify an arrangement of a desk which can integrate a mechanism to adjust a height of a top plate and a mechanism to adjust a level of a top plate, in a desk in which a height of a top plate can be varied within a predetermined range through a height adjust mechanism, the desk is so arranged that the top plate is supported by a plurality of expansible leg support posts, and the height adjust mechanism makes use of the leg support posts and can adjust an expansile amount of the leg support posts individually within the predetermined range through a little larger than the predetermined range.

This invention relates to a desk and, more particularly, to a desk whichis preferably used in offices or at home.

BACKGROUND ART

Desks are generally standardized at a height of a top plate to a certaindegree. However, if several different standards exist or the standardvaries in countries, a desk having a different specification has to bemade according to the standard. In addition, a learning desk forchildren has to be changed in a height of a top plate in accordance witha growth degree of a child. However, it is a waste if the desk is tradedfor a new one every time the child grows.

Under these circumstances, a desk wherein a height of a top plate can bechanged by means of a height adjust mechanism has been developed and isin use presently.

Generally, in an ordinary desk, adjusters are provided at a plurality ofpositions where each of a bottom end of the legs is supported and leveladjustment by means of the adjusters makes it possible to cooperate withan uneven floor on which the desk is placed. In the above-mentioneddesk, an adjuster adjust mechanism and a height adjust mechanism areseparately incorporated into the desk. This increases a number ofcomponents and processing steps and it would become a factor whichhinders a promotion of lowering cost and weight or of simplifying anarrangement of the desk.

DISCLOSURE OF THE INVENTION

In order to solve the above-mentioned problems, attention is paid to apoint that both an adjuster adjust mechanism and a top plate heightadjust mechanism are done by an operation of up and down. From the aboveviewpoint, these functions are carried out by a common mechanism in thedesk of the invention.

More specifically, the desk in accordance with the invention ischaracterized by that a height of a top plate can be changed through aheight adjust mechanism within a predetermined range which is largerthan a level adjust amount by means of an ordinary adjuster wherein thetop plate is supported by a plurality of expansible leg support posts,and the height adjust mechanism makes use of the leg support posts andcan adjust an expansile amount of the leg support posts individuallywithin the predetermined range through a little larger than thepredetermined range. In the above case, the range within thepredetermined range through a little larger than the predetermined rangemeans both a range within the predetermined range and a range within alittle larger than the predetermined range.

The leg support post may comprise a support post member and a groundingmember which is arranged at the lower end of the support post member andwhich can protrude or recede, and the height adjust mechanism may beprovided with a fixing member which fixes the grounding member to thesupport post member at a predetermined position.

To obtain an improved operationability and stability with a simplearrangement, it is effective if the leg support post comprises a supportpost member and a grounding member which is arranged at the lower end ofthe support post and which can protrude or recede, and the height adjustmechanism comprises a screw means which helically connects the supportpost member and the grounding member with allowing the support postmember to make an up and down movement.

More concretely, it is effective if the screw means comprises a nutmember which is mounted on the support post member unrotatably and ascrew shaft which projects upward over the grounding member and theprojecting side is helically connected with the nut member.

It is preferable that the grounding member is provided with a handlingportion which is to allow the screw shaft to screw up and down relativeto the nut member.

To improve appearance regardless of a position at which the leg supportpost is adjusted, it is preferable that a cover is mounted on thesupport post member with the upper end thereof allowed to make a slidingmovement up and down and the cover is so arranged that a lower endthereof covers the grounding member and the handling portion.

In the above case, to secure an improved operationability, it iseffective if a movable position which alternatively exposes the handlingportion is provided at a part of an underside of the cover.

As described above, the desk in accordance with the invention has anarrangement in which the top plate is supported by a plurality ofexpansible leg support posts and the height adjust mechanism makes useof the leg support posts and can adjust an expansile amount of the legsupport posts individually within the predetermined range through alittle larger than the predetermined range.

In accordance with the arrangement, when each of the leg support postsis adjusted to change substantially the same amount by operating theheight adjust mechanism, the height of the top plate is also changedwithin the predetermined range in accordance with the adjusted amount.When several of the leg support posts are adjusted to change just alittle, the level of the adjusted leg support posts only is changed,thereby to be able to cope with an uneven floor.

As mentioned above, the height adjust mechanism carries out a functionto adjust not only the height of the top plate but also the level ofeach leg support posts. Therefore, the cost and the weight of the deskcan be reduced due to a common component used for different objects, andappearance of the desk can also be kept in a good looking condition. Inaddition, with the adjustment applied, it becomes possible toeffectively adjust the top plate so as to be horizontal when placed on asteeply inclined floor.

As a result, it becomes possible for the height adjust mechanism tocarry out a function not only to adjust the height of the top plate butalso to adjust a level of every leg support post individually and it caneffectively conduct adjustment to an inclined floor.

If the leg support post comprises a support post member and a groundingmember and the height adjust mechanism is provided with a fixing memberwhich fixes the grounding member to the support post member at apredetermined position, the leg support post can be expansible with asimple arrangement and stability can also be secured.

Especially, if the leg support post comprises a support post member anda grounding member and the support post member and the grounding memberare connected by a screw means which comprises a nut member and a screwshaft, an improved operationability and stability can be obtained with asimple arrangement. In addition, since the leg support post can be keptin an adjusted position by itself when expansile amount is adjusted,there is no need of other fixing operation and fixing members.

If the grounding member is provided with a handling portion which givesa force to operate the screw means, the handling portion and thegrounding member can be made integrally, resulting in a merit in aprocessing step.

If a cover is mounted on the support post member with the upper endthereof allowed to make a sliding movement up and down and the cover isso arranged that a lower end thereof covers the grounding member and thehandling portion, appearance of the leg support post can be kept in agood looking condition no matter what position the leg support post isadjusted.

In this case, if a movable member which alternatively exposes thehandling portion to a side of the cover is mounted on the lower end ofthe cover, there is no need to move the cover so as to slide every timethe handling portion is handled, thereby to simplify the operation ofadjusting a level of the leg support post.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall perspective view showing one embodiment of theinvention.

FIG. 2 is a partially cut out perspective view of the embodiment.

FIG. 3 is an exploded perspective view of a leg support post of theembodiment.

FIG. 4 is an elevational cross sectional view of the leg support post.

FIG. 5 is an explanatory view corresponding to FIG. 4.

BEST MODES OF EMBODYING THE INVENTION

The invention will be described in detail with reference to anembodiment thereof shown in the accompanying drawings.

The desk has an arrangement, as shown in FIGS. 1 through 4, in whicheach of four leg support posts 1 is connected at the upper end thereofthrough a frame 2 and a top plate 3 is supported by the frame 2.

Each of the leg support posts 1 is of a square pipe and arranged at fourcorners or near the corners of the rectangular top plate 3 with an upperend of the leg support post 1 facing to an underside of the top plate 3.The frame 2 comprises a pair of right and left frame members 21 whichconnect the front and back leg support posts 1 along a direction ofdepth at adjacent the top end of the inner surfaces which face eachother, a front frame member 22 which connects the right and left legsupport posts 1 arranged front side along a direction of width atadjacent the top end of the inner surfaces which face each other, andreinforcing frame member 23 which connects the right and left framemembers 21 at a little front of the center of the inner surfaces whichface each other. This frame 2 constitutes a self standing structuretogether with each of the leg support posts 1 by prohibiting each otherfrom being apart. Each of the right and left frame members 21 and thefront frame member 22 is made of a common extruded form of a materialhaving rigidity such as aluminum which is cut in a required length andis provided with a rail groove 21 a, 22 a which opens at one side facinginward of the frame members 21, 22. The reinforcing frame member 23 alsois made of substantially the same extruded form of a material havingrigidity such as aluminum which is cut in a required length and isprovided with an opening as a rail groove 23 a which opens at both sidesof the reinforcing frame member 23.

In this embodiment, brackets 4 each having a face 4 a to support the topplate 3 are mounted on the right and left frame members 21 at twopositions thereof, namely back and front of the right and left framemembers 21 by making use of the above mentioned rail groove 21 a andanother bracket 4 having a face 4 a to support the top plate 3 ismounted on the reinforcing frame member 23 at the center thereof bymaking use of the rail groove 23 a. Then the top plate 3 is placed onthe faces 4 a of the above-mentioned five brackets 4 and fixed theretoby means of a screw from underside of the top plate 3. The top late 3has an arrangement in which a plurality of materials for a top plate areoverlapped along a direction of depth so as to show a grain of woodalong a direction of width. With this arrangement, the top plate 3produces a high strength against a load which is applied by placingsomething even if the top plate 3 is supported by the brackets 4 at onlyfour corners and the center thereof.

With the above arrangement, in this embodiment, the top plate 3 is soarranged that the height can be varied, for example, within apredetermined range of approximately 80 mm through the height adjustmechanism 5.

In the height adjust mechanism 5, for making use of the leg supportposts 1 as a construction element, the leg support posts 1 have anarrangement in which a support post member 11 and a grounding member 12are expansibly connected to each other and an expansile amount of eachleg support posts 1 can be adjusted individually within theabove-mentioned predetermined range through a little larger than therange by means of a screw means 6.

More specifically, the support post member 11 is made of a materialhaving rigidity such as aluminum which is extruded into a square pipe.On the bottom end of the leg support posts 11 a nut member 61 having athreaded hole 61 a at the center thereof is mounted with a part of thenut member 61 inserted thereinto so as to restrict the nut member 61from being rotated.

In the grounding member 12, a bottom end thereof forms a grounding area12 a and a side area 12 b serves as a handling portion which has a shapeof a nut with which a wrench is to be engaged from a side direction. Anda screw shaft 62 projects upward from the upper face of the handlingportion 12 b. The screw means 6 comprises the threaded hole 61 a and thescrew shaft 62 and has an arrangement in which a projecting side of thescrew shaft 62 is helically connected to the threaded hole 61 a of thenut member 61. An effective range of the screw means 6 in which thescrew shaft 62 is prevented from being out of joint of the threaded hole61 a is set at least a little larger than the above-mentioned 80 mm.

Further, in this embodiment, a rectangle pipe cover 14 which is a littlelarger than the support post member 11 made of resin or something likethat is arranged so that the upper end of the cover 14 fits over thesupport post member 11. On the inner face of the upper end of the cover14 mounted is a close member 14 a which closes a clearance between thesupport post member 11 and the cover 14. The cover 14 is arranged withan inner face 14 b thereof affixed to an outer face 61 b of the nutmember 61. Then the cover 14 is affixed to two points, namely the outerface 11 a of the support post member 11 and the outer face 61 b of thenut member 61 through the close member 14 a so as to make a slidingmovement up and down without being loosened. The cover 14 is kept in acondition so as not to be apart from the support post member 11 becausethe close member 14 a is kept in a tight contact with the cover 14 andthe support post member 11 if no force is applied thereto. The cover 14is so arranged that a lower end thereof covers the grounding member 12.

A movable member 15 which alternatively exposes the handling portion 12b to a side of the cover 14 is mounted on the lower end of the cover 14through a limit member 16. The movable member 15 is provided with anengaging claw 15 which faces outward at the upper end thereof and ahollow portion 15 b which covers the grounding member 12 at the lowerend thereof. The limit member 16 is provided with a clearance 16 a whichengages the engaging claw 15 with the lower end thereof so as to allowthe engaging claw 15 to make an up and down movement and which restrainsthe up and down movement of the engaging claw 15 within a given range.The movable member 15 can be moved within the given range so as toalternatively expose or cover the side of the handling portion 12 b. Inthe limit member 16, the upper face 16 c serves as a role to set a limiton the lowest position of the nut member 61 and a through hole 16 bthrough which the screw shaft 62 is to be passed is provided at thecenter of the limit member 16.

Next a method to deal with this embodiment will be explained. First,lift up the movable member 15 as shown in FIG. 5 from a condition shownin FIG. 4 so as to expose a side of the handling portion 12 b. Next,engage a wrench which is not shown in drawings with the handling portion12 b and rotate the screw shaft 62 to a predetermined direction so as tomove the nut member 61 along an axial direction of the screw shaft 62.Then an amount of the grounding member 12 projecting from the supportpost member 11, namely, an expansile amount L of the leg support post 1as a whole can be adjusted within a range as far as the nut member 61engages with the screw shaft 62. With the same manner applied to all ofthe other leg support posts 1, the height of the top plate 3 can bechanged within a range, for example, 680 mm to 760 mm. It is a matter ofcourse the above operation can be done with the desk placed upside downand lower end of the leg support posts 1 protruded upwardly.

In case the top plate 3 is not stably placed horizontally due to anerror of adjustment or unevenness of the floor F even if the desk isplaced on a floor F with the grounding area 12 a of the leg support post1 being grounded after the height of the top plate 3 is adjusted, adjustonly the required leg support post 1 in the same manner as in the caseof the above so as to move the grounding member 12 a very slight amountwith a wrench applied to the handling portion 12 b of the required legsupport post 1. Then the height of each leg support posts 1 can beadjusted individually.

As mentioned above, in this embodiment, the height adjust mechanism 5which makes use of expansion and contraction of the leg support post 1carries out a function to adjust not only the height of the top plate 3but also the level of each leg support posts 1. Therefore, the number ofcomponents and the number of working steps required for manufacture andassembly is greatly reduced as compared with conventional desks in whichthese functions are carried out by different mechanisms, thereby toreduce the cost and the weight of the desk as a whole and to simplifythe arrangement of the desk.

In addition, with applying the adjustment, if, for example, one pair ofthe two pairs of the leg support posts 1 which support two sides of thetop plate 3 facing each other are adjusted to have the same expansibleamount and the other pair are adjusted differently, the top plate 3 canbe adjusted so as to be horizontal when placed on a steeply inclinedfloor F. Further, since these functions accompany to the leg supportpost 1 alone, in other words, do not accompany to the top plate 3 or thelike, an arrangement of the top plate 3 can be simplified and this makesit possible to prevent the space under the desk from being unreasonablyreduced and to improve the appearance of the leg support post 1.

Especially, in this embodiment, since the leg support post 1 comprisesthe support post member 11 and the grounding member 12 which is arrangedat the lower end of the support post member 11 and which can protrude orrecede, and the height adjust mechanism 5 comprises the screw means 6which helically connects the support post member 11 to the groundingmember 12 with allowing the support post member 12 to make an up anddown movement, a stable and smooth movement can be obtained with anextremely easy operation and the grounding member 12 can be securelykept at a desired position by making use of the self-lock mechanism ofthe screw means 6 without any other fixing members.

Since the screw means 6 basically comprises the nut member 61 which ismounted on the support post member 11 unrotatably and the screw shaft 2which projects upward over the grounding member 12 and the projectingside is helically connected with the nut member 61, required functioncan effectively be obtained with the least required number ofcomponents. In this case, since the handling portion 12 b for rotatingthe screw shaft 62 is formed in the side of the grounding member 12, acommon component can be shared, and since the handling portion 12 b canbe operated just near the grounding member 12, it becomes easy tooperate the handling portion 12 b.

Further, in this embodiment, the cover 14 is attached to the supportpost member 11 with an upper end thereof allowed to make a slidingmovement up and down, and the lower end of the cover 14 always coversthe grounding member 12, even if the leg support post 11 is expanded,for example, as shown in FIG. 4 and 5, resulting in keeping anappearance of the leg support post 1 in a good looking condition.

In this case, since the movable member 15 which alternatively exposesthe handling portion 14 b to the outside of the cover 14 is provided atthe lower end of the cover 14, there is no need of moving the cover 14so as to slide every time the handling portion 14 b is handled, therebyto simplify the operation of adjusting a level of the leg support post1.

The component parts are not limited to the illustrated constructions,but there may be various modifications and changes without departingfrom the scope of the invention. For example, this does not exclude anarrangement in which a fixing member such as a screw fixes the supportpost to the grounding member which constitutes the leg support post at apredetermined position. The above-mentioned position is just oneembodiment of the invention, and it is needless to say that theadjustable amount of the top plate or the level can be set at any amounttailored to an object or a usage of the desk. Further, the deskdescribed in this specification also includes a concept of, so to speak,a table.

Possible Applications in Industry

As mentioned above, the desk in accordance with the invention is usedwhen it is needed that a height of the top plate be changed according toa user's requirement, especially preferably used for a learning desk forchildren which is required to change a height of the top plate accordingto a growing rate of the child. The desk is also preferably used in acase a floor on which the desk is to be placed is steeply inclined.

What is claimed is:
 1. A desk comprising a top plate supported by aplurality of expansible leg support posts wherein a height adjustmechanism adjusts a height of said top plate within a predeterminedrange, said height adjust mechanism comprising said expansible legsupport posts wherein said height adjust mechanism can adjust anexpansible amount of said leg support posts individually within saidpredetermined range through an amount larger than said predeterminedrange and wherein each of said leg support posts comprises a supportpost member and a grounding member located at the lower end of thesupport post member, wherein the grounding member may move to protrudefrom or recede into the support post member and the grounding memberfurther comprises a handling portion, and the height adjust mechanismcomprises a screw means which helically connects said support postmember and said grounding member, said screw means providing an up anddown movement through an operation of said handling portion, the deskfurther comprising a cover mounted on said support post member, saidcover being movable up and down by sliding and a lower end of said covercovers said grounding member and said handling portion.
 2. The desk ofclaim 1 wherein each of said leg support posts comprises a support postmember and a grounding member located at the lower end of the supportpost member, wherein the grounding member protrudes from or recedes intothe support post member, said height adjust mechanism further comprisinga fixing member which fixes said grounding member to the support postmember at a predetermined position.
 3. The desk of claim 1 wherein saidscrew means comprises a nut member mounted on the support post memberunrotatably and a screw shaft projecting upward from the groundingmember and helically connected with said nut member.
 4. The desk ofclaim 3 wherein said grounding member further comprises a handlingportion to screw said screw shaft up and down relative to said nutmember.
 5. The desk of claim 4 further comprising a movable member,which alternatively exposes the handling portion, provided at a part ofan underside of the cover.